Method and apparatus for molding seamless hollowware articles



Dec. 7, 1937. c c. WARREN METHOD AND APPARATUS FOR MOLDING SEAMLESS HOLLOWWARE ARTICLES Filed June 15, 1937 3 Sheets-Sheet l Dec. 7, 1937. c. c. WARREN METHOD AND APPARATUS FOR MOLDING SEAMLESS HOLLOWWARE ARTICLES Filed June 15, 1937 3 Sheets-Sheet 2 v gwuc/wfm C al 'y 6. 71 0/49;

Dec. 7, 1937. c. c. WARREN METHOD AND APPARATUS FOR MOLDING SEAMLBSS HOI LOWWARE ARTICLES Filed June 15, 1937 3 Sheets-Sheet 3 :Lwcmk 00/14? 67 71 arrgp H m v"all;

Patented Dec. 7, 1937 PATENT OFFICE- METHOD AND' APPARATUS FOR MOLDING SEAMLESS HOLLOWWARE ARTICLES Calvin 0. Warren, South Dayton, N. Y., assignor of one-third to Edward Amacher and onethird toGeorge W. Percy, both of South Dayton, N. Y.

' H Application June 1.5, 1937, Serial 'N... 148,370

Claims. (01. 22-190) This inventionrelates to a method and apparatus for the molding of seamless hollow ware articles and more particularly to hollow ware articles having restricted neck portions.

5 This invention further relates to an'improved material used in the formation of the molding apparatus for making hollow ware articles with restricted'neck portions.

This invention further contemplates the formation of vcast metal articles, preferably made of light metal. such as aluminum oralloys thereof.

The method broadlycontemplates the casting of an article having a hollow body portion and a restricted neck portion in such manner that the molds may be removed from the outside and from within.'the article witha minimum of effort and in such manner that the material which makes up the mold may be used again.

The particular molding material employed in the. formation of the .molding apparatus constitutes an important. part of'this. invention. It is important in casting hollow articles having re stricted neck portions, to employ an inner mold, which issubstantially rigid and at the same time maybe removed through the restricted opening in .a facilemanner.

In order toobtain the above result, my invention contemplates the use of a molding material made up, of a mixture of plaster of Paris and a fibrous material. Thefibrous material'may be asbestos or the like. The asbestos and plaster of Paris is used in equal proportions and mixed to a stiff paste. Thereafter. the mixture is packed into suitable forms defining the shape of the mold desired and then placed in an oven to be thoroughly dried. l The molds thus obtained are then sand papered toobtain a smooth surface to thus provide a smooth. surface to the article tobe cast.

'A'mold formed in" the above manner is sub- 4 stantially rigid and upon completion of the casting operation which consists of pouring molten metal into the molds, the mold and the article are-together placed in' avat ofwater where the water will turn the mold into a'pasty pulp. The pasty pulp can then be readily removed leaving the molded article free of the mold. The pulp thus removedcan again be used in making new molds or forms.

In order to illustrate the present invention as applied to. a specificarticle, the present invention will be more specifically described in con- .nectionwith amilkican of the design having a restricted. neck portionand an outwardly flared portion above the restricted portion.

.1. In. the construction of milk'cans of the type matter.

referred to above, the usual practice has been to form the can of a plurality of parts which are welded or riveted together to form the finished can. The presence of joints of any form in a V milk can is highly objectionable in that the joints 5 may be easily ruptured and furthermore provide a gathering place for dirt and other foreign With my improved method of casting, it is possible to provide a seamless can which is of maximum strength and has an internal surface 10 free of sharp edges or crevices.

Thus the principal object of my invention is to provide an improved method of forming seamless hollow ware articles.

Another object of the invention is to provide 15 a seamless milk can having a structure affording maximum strength with a minimum of material and having an internal surface free of edges or crevices which would prevent thorough cleaning thereof or assist in the adherence of dirt or other foreign matter.

A further object of the invention is to provide a container of the type referred to which may be manufactured in a simple and economical manner. A still further object is to provide an improved method of also forming a seamless lid for the milk can.

. Other objects and advantages of the invention will appear as the description of the drawings proceeds. I desire to have it understood, however, that I do not intend to limit myself to the particular details shown or: described, but that I intend to include as part of my invention all such obvious changes and modifications as would oc our to persons skilled in this art.

For accomplishing the above objects of their;- vention, a milk can has been constructed as herein shown and described, and for a complete understanding of the invention, reference is to be had 40 to the following description considered with reference to the accompanying drawings.

In the drawings:

Fig. 1 is an exploded view in perspective of the mold for the can.

Fig. 2 is a top plan view of the mold.

Fig. 3 is a vertical section through the female part of the mold showing the core about to be inserted therein.

Fig. 4 is a vertical sectional view through the 5 female part of the mold with the cover positioned in place.

Fig. 5 is a sectional view of the mold showing the core centering and sealing member, before the mold is set up in its inverted molding position.

Fig, 6 shows a sectional view through the mold with the metal poured therein.

Fig. 7 is a side elevation of the seamless can formed by the mold.

Fig, 8 is a fragmentary detail view looking into one of the recesses formed in the female mold member for forming integral handle receiving ears on the can.

Fig. 9 is an exploded view in perspective of the mold employed for forming the can lid.

Fig. 10 is a vertical sectional view of the lid forming mold.

Fig. 11 is a view of the completed lid shown partly in section, and

Fig. 12 is a View of the finished seamless can with the lid thereon.

Referring to the drawings in detail, and more particularly to Fig. 3, l denotes the female mold member having a substantially cylindrical portion 2, at the lower end of which is formed a frustro-conical portion 3, converging surface 4 and outwardly flared portion 5. The female member is provided with a plurality "of ventilation openings 6 to permit the escape of air during the pouring of the molten metal into the mold. In the cylindrical portion of the mold, I provide spaced grooves l for'the purpose of forming reinforcing ribs on the can. Although the grooves are shown at the extremities of the cylindrical portion 2, the same can be placed at any point of the female member. Recesses or depressions 8 are provided in the frustro-conical portion 3 of the mold to provide for integral lugs on the can, the purpose of which will be hereinafter more fully explained.

The inner core member designated at 9, and more clearly shown in Fig. 4, comprises a substantially cylindrical body portion In, an inwardly converging frustro-conical portion I l, and an out- Wardly flared 'neckportion l2. The'bottom [3 of the core member is made concave to provide a thickened bottom 'for the can.

Referring to Figures 1 and '2, I4 denotes a spacing and sealing member being shaped in the form of a frustrum and of such size as to fit within the outwardly flared portion 5 of the female mold member and providing a space therebetween. The upper surface l5 of the member [4 being of substantially the same area as the lower surface of core 9.

Attached'to the spacer M, by means of a screw I6, is a cover plate I! having a sheet of asbestos paper l8 secured to the inner surface thereof. The cover plate I1 is of such size as to cover the spacer member and the lowersur'face of the female mold member so as to close off the space between the inner core member 9 and the female member I. The'screw member l6 besides acting as 'a detachable securing means between the spacer I 4 and the core member, has the additional function of slightly adjusting the space between the inner and outer molds so as to vary the thickness of the molded article.

It is important at this time to disclose the material of which the mold and core are formed, the particular material used forming 'an important part=of this invention.

In forming a seamless milk can of the type disclosed in the accompanying drawings, it is necessary to employ a molding apparatus which is both rigid and may be readily removed. I accomplish these results byusinga plastic material which is baked in an oven to become substantially rigid an'd'which is softened-and turned to a pulpy mass by inserting the same in a liquid bath, such as water.

Specifically, my invention contemplates the use of substantially equal parts of asbestos fibre and plaster of Paris. These twoingredients are mixed to a stiff paste, then packed into the desired forms and then placed into an. oven to be thoroughly dried. They are then removed and sand papered to obtain a smooth surface. A mold formed in the above manner can be readily softened by insertion of the same in a liquid bath.

Although I have disclosed the ingredients as being asbestos fibres mixed with plaster of Paris, my invention contemplates the use of other ingredients which have the same or similar characteristics as the specific ingredients mentioned above and which will function in the same manner to obtain the desired results.

Referring to Fig. 7, there is disclosed the can l9 just subsequent to the removal of the same from its liquid bath. The manner of producing can I9 is as follows:

Referring to Figures 3, 4 and -6,the core member 9 is first inserted in the female member so that surface II of the core member rests on portion 3 as clearly seen in Fig. 4. The spacer member I4 is then inserted in the lower portion of mold l and connected to the core member by means of screw l6, thereby serving to space the core member from the female member, the desired thickness of can IS. The cover member I! is then secured in place and closes off the space between the core and the mold. The core member is of such size as to terminate in a plane below the upper surface of the female member.

The molten metal which may be aluminum or an alloy thereof is then poured into the space between the mold and the core until the entire space up to the upper surface of the femalemember is filled with the molten metal. Upon cooling of the metal, the mold is placed in avat of water or other liquid (not shown). The mold then becomes a pasty pulp and can .be readily removed, leaving the can in the .form as disclosed'in Fig. 7 after which it is given the finish ing touches as will be explained below. The pasty pulp mentioned above may be used again if desired.

Again referring to Fig. 7, .nibs which are formed during the molding operation due to the ventilation openings 6, are filed off or otherwise removed. 'Due to the presence of the depressions .or recesses 8 in'the female member, integral lugs 2| are formed on the upper portion of can I 9. These lugs are then drilled and receive handles 22'as shownin Fig. 12. 'This manner of providing handles produces a strong construction,

doing away with the usual manner of riveting or welding handles in place, thereby lessening the cost of manufacture.

.Annular'inforcing .ribs 23 are also integrally formed on the body of the can I9 due to the rib forming recesses I .in the female mold. These ribs provide fora stronger can.

Another phase of the invention relates to a simple method and apparatusfor forming a one piece seamless lid for the milk can herein described.

The lid 32 is disclosed in Fig. 11 and the apparatus for forming the lid is disclosed in Figs. 9 and 10-wherein '24 denotes the lower mold sec tion in the form of a shallow dish, upper mold section 25 having a vertical'flange 26'which frictionally engages mold 24 to hold the sections-in temporary engagement. The upper'mold section holds the core member 30 spaced from the mold sectionsa sufficient distance depending on the desired thickness of the lid. V 1

Members 24, 25 and 30 may be made of the same material as the can, but as herein disclosed only the inner core member is made of plastic material and the other sections maybe made of metal. The molds are so shaped that the outer sections may be readily stripped from the lid even though made of metal as clearly disclosed in the drawings.

The manner of forming the lid is as follows: The molds are assembled as disclosed in Fig. 10, the molten metal poured in through frame member 21 until the molten metal reaches the top edge of core 30. The metal is allowed to cool, after which the outer sections are readily removed. The lid with the core member is then inserted into a liquid bath which turns the core member into a pasty pulp permitting the same to bepoured out, thus leaving the finished seamless lid, the same being shaped to snugly yet removably fit in the neck and mouth of the milk can.

Thus, it is seen that the constructions herein shown and described are'well adapted to accomplish the objects of the present invention. It will be understood, however, that the invention may be embodied otherwise than here shown and that in the embodiments illustrated certain changes in the construction and arrangements may be made. Therefore, I do not wish to be limited precisely to the constructions herein disclosed except as may be required by the appended claims considered with reference to the prior art.

Having thus described the invention,'what is claimed is: i f

a 1. Molding apparatus for forming seamless milk cans of the type having restricted openings which comprises an outer female member whose inner wall is substantially cylindrical and terminates in a frustro-conical portion converging inwardly, an inner core member whose outer surface comprises a cylindrical portion the lower part of which forms a frustro-conical surface converging inwardly, said core member being of such diameter as to provide a space between the core member and the female member, a spacing 7 member fitting within'the lower portion of the female member, means for detachably securing the spacing member to the core member, a cover plate secured to the outer surface of the spacing member and covering the lower surface of the female member, the upper surface of the core member terminating in aplane slightly below the upper surface of the female member.

2. Molding apparatus for forming seamless milk cans of the type having restricted openings which comprises an outer female member whose inner wall is substantially cylindrical and terminates in a frustro-conical portion converging inwardly, an inner core member whose outer surface comprises a cylindrical portion the lower part of which forms a frustro-conical surface converging inwardly, said core member being of such diameter as to provide a space between the core member and the female member, a spacing member fitting within the lower portion of the female member, means for detachably securing the spacing'member to the core member, a cover plate secured to the outer surface of the spacing member and covering the lower surface of the female member, the upper surface of the core member terminating in a plane slightly below.

tween the core member and the female member,

a spacing member fitting within the lower portion of the female member, means for detachably securing the spacing member to the core member, a cover plate secured to the outer surface of the spacing member and covering the lower surface of the female member.

4. Molding apparatus for forming seamless milk cans which comprises an outer female member whose inner wall is substantially cylindrical, an inner core member whose outer surface comprises a cylindrical portion, said core member being of such diameter as to provide a space between the core member and the female member, a spacing member fitting within the lower portion of the female member, means for detachably securing the spacing member to the core member, a cover plate secured to the outer surface of the spacing member and covering the lower surface of the female member, the apparatus consisting of a substantially rigid material capable of softening in liquid.

5. Molding apparatus for forming seamless milk cans of the type having restricted openings which comprises an outer female member whose inner wall is substantially cylindrical and terminates in a frustro-conical portion converging inwardly, said female member having a plurality of small openings in the side wall thereof, the frustroconical portion of the female member having two oppositely disposed recesses therein, an inner core member whose surface comprises a cylindrical portion the lower part of which forms a frustro-conical surface converging inwardly, said core member being of such diameter as to provide a space between the core member and the female member, a spacing member fitting within the lower portion of the female member, means for detachably securing the spacing member to the core member, a cover plate secured to the outer surface of the spacing member and covering the lower surface of the female member, the upper surface of the core member ter- 

